The present invention relates to a control device and method for an automatic transmission.
An automatic transmission mounted on a vehicle or the like is structured so as to be capable of driving the vehicle at an appropriate gear ratio without a shift operation by a driver, by automatically judging a gear ratio (shift speed) based on an accelerator opening and a vehicle speed particularly during forward driving. However, in recent years, in order to meet such a demand for sports driving and a delicate selection of engine braking for example, automatic transmissions have been proposed that also allow a so-called manual shift operation in which the driver can select a gear ratio (shift speed) (see, for example, Japanese Patent Application Publication No. JP-A-10-324169).
In recent years, since improvements in vehicle fuel consumption and so on are required, multi-speed automatic transmissions, such as those achieving six or more forward speeds, are becoming prevailing in the category of stepped automatic transmissions. Moreover, automatic transmissions such as belt type CVTs that steplessly change speed, are also structured so as to be capable of selecting simulated shift speeds by providing finely spaced gear ratios (for example, 6 stages or more).